Automatic power transmitting mechanism



Sept. 5, 1939. R. P. LEWIS AUTOMATI C POWER TRANSMITTING MECHANISM Filed Sept. 20, 1932 3 Sheets-Sheet l 3mm iPaber/ P Jew/J p -.5, 193.9. I R. P. LEWIS 2,171,334

AUTOMATIC POWER TRANSMITTiNG MECHANISM gvwowto'n I q/zmwwm' Patented Sept. 1939 UNITED' STATES AUTOMATIC POWER TRANSMITTING MECHANISM Robert P. Lewis, Toledo, Ohio, assignor' to The Automatic Drive &

Transmission Company,

New York, N. Y., a corporation of New Jersey Application September 20, 1932, Serial No. 634,048

. 12 Claims.

The present invention relates to automatic or self-operating drive and clutch mechanisms for transmitting power from a driving shaft to a driven shaft, and more particularly the present invention relates to automatic drive and clutch mechanisms especially designed and adapted to be used in connection with motor driven vehicles.

In applications Serial No. 595,184, filed February 25, 1932, and Serial No. 606,238, filed April 19, 1932, automatic or self-operating drive and clutch mechanisms of the character above mentioned are disclosed, and broadly stated, one of the objects of the present invention is to refine certain details of the constructions there shown and to provide clutch mechanisms that are very efflcient and effective and which particularly lend themselves to low cost, modern production methods.

More specifically, one of the objectsof the pres- 20 ent invention is to provide drive and clutch mechanisms of the character mentioned wherein novel means is employed for associating the centrifugal weights with the automatic plate and to provide an improved form of centrifugal weight. 25 In view of the fact that more heat is generated during operation of drive and clutch mechanisms of the character mentioned than in ordinary manually operable clutches of like capacity, they must be capable of dissipating heat very rapidly and it is accordingly another object of the present invention to provide clutch mechanisms that arecapable of rapidly dissipating heat from the elements thereof by radiation and convection as well as efficiently disposing of solid lubricant and other material that may be freed from the clutch facings during operation.

Another object of the present invention is to provide drive and clutch mechanisms of the character indicated wherein the driving pressure is evenly distributed about the entire areas of the clutch plates, giving the clutch facings a long life, and producing smooth and efiicient clutch operation.

Still another object of the present invention is to provide drive and clutch mechanisms of the character mentioned wherein novel means are employed for keying the automatic plate to the flywheel so that the automatic plate is caused to rotate therewith, and yet is free to move axially 5 55 idling and the plates are disengaged, the positive thereof for clutching and declutching movements.

plate .will be disposed in absolute parallelism with the automatic plate, and the driven member, so that when the automatic. plate comes into contact with the driven member, the driven member will be caused to contact with the entire area of the positive plate simultaneously and grabbing or harsh clutch operation is avoided. r

A still further object of the present inventiton is to provide drive and clutch mechanisms of the self-operating or automatic type, wherein the positive plate may be adjusted angularly with respect to the automatic plate, whereby absolute parallelism of the two plates may be readily established.

Another object of the present invention is to provide an improved vibration and impulse dampener in combination with clutch and drive mechanisms of the character mentioned that in addition to compensating for torsional vibrations of the crankshaft, and smoothing out, the pulsating torque delivery inherent with an internal combustion engine having a low number of cylinders particularly at the lower speeds when picking up the load in slipping drive so related to the clutch elements that it will afford a resilient connection between the driving and driven shafts, and the slipping drive and clutch action will be materially improved. v

A further object of my invention is to provide drive and clutch mechanisms of the character indicated wherein means are provided for effectively lubricating the pilot bearing.

Other objects of the present invention will become apparent as the description thereof proceed's in connection with the drawings. In the drawings:

Figure 1 is a longitudinal sectional view of a clutch mechanism'forming part of the present invention, the section through the flywheel being taken approximately on the line l--l of Figure 2.

Figure '2 is aview of the drive and clutch mechanism disclosed in Figure 1 as it appears -when viewed from the right hand side of that fi ure and with the mechanism rotated through the angle of 60 and with the clutch housing and throwout mechanism removed for sake of clarity of illustration.

and with parts in section of the driven member employed in the clutch mechanism disclosed in Figure 1.

Figure 3 is a fragmentary view with parts inthe line -5 of Figure Figure 5 is a detailed sectional view taken on 2 on a slightly enlarged scale.

Figure 6 is a view taken approximately on the line 6-6 of Figural, looking in the direction of the arrows.

Figure 7 is a plan view of one of the centrifugal weights employed in the clutch mechanism illustrated in Figure 1.

Figure 8 is a fragmentary view illustrating the cooperation of a centrifugal weight .with the groove formed in the automatic plate of the drive and clutch mechanism shown in Figure 1.

Figure 9 is a longitudinal sectional view of my improved drive and clutch mechanism embodying a modified throwout mechanism and spring mechanism incorporated therein.

Figure 10 is a section taken on line Ill-40 of Figure 9 as seen when viewed in the direction of the arrows when the mechanism is rotated through the angle of 60.

Figure 11 is a view taken on line |l-il of Figure 9 looking in the direction of the arrows.

Referring to the drawings, wherein like reference characters designate like parts throughout the several figures thereof, a housing generically designated as l houses the mechanism and is provided with the usual hand opening 2, which is closed by screen 3 for the purpose of allowing free entrance and exit of air from the housing and for preventing the introduction of extraneous matter therein for a purpose that will presently appear. Secured to flange 4 of engine or driving shaft 5 by means of bolts 6 in well known manner is web portion 1 of a special type of flywheel 8. The periphery of flywheel 8 is provided with the usual starting gear 9.

Disposed in axial alignment with shaft 5, and

mounted for rotation, is driven shaft I! which is reduced at i2 at one end and journaled in a suitable anti-friction bearing assembly 13, secured in a bore in the end of shaft 5.

Driven shaft II is adapted to have the other end thereof operably connected to a suitable gear changing apparatus of well known construction (not shown) for amplifying the torque applied to the final driven member. Driven shaft H has a splined portion H on which a correspondingly splined hub. I5 is slidably mounted. Hub I5 is resiliently connected to driven disk I! by means of a dampener mechanism that will presently be described. Disk ii is provided with a plurality of radially extending slots l8, which extend to the periphery-thereof and terminate at their inner ends in openings IB'. Slots l8 give. disk ii extreme flexibility in an axial direction and permit accommodation to slight angular misalignment of the clutch plates, while apertures i8 provide distribution of air each side of disk I! as will be more particularly'pointed out.

Each face of disk i1 near the periphery thereof is provided with a facing l9 and 20 respectively, which may consist of any material that has the required characteristics to give the correct frictional gripping force, and at the same time has wearing qualities adapting it for this purpose. I'prefer, however, to use the lubricated type of material disclosed in B. Heinrich, Serial No. 580,1 fi December 10th, 1931, which issued as Patent 1,979,880 on November 6, 1934, embodying large percentages of graphite, which in practice have given very satisfactory results in a slipping drive and clutch mechanism of this character. Frictional faces I9. and 2|! may be secured to disk I] yieldingly transmitting torque thereto givendisk direction, hub

'mitting shocks from one the application of .Charles.

in any suitable given a slightly curved configuration for a purpose that will presently appear. The driving recesses formed in flange 22 are shown in the present instance as being of six in number, and while this number has been found to give very good results'in practice, it is to be understood that the recesses could be more or less than six in number without sacrificing the advantagesof the present invention. Flange 22 rather snugly flts in an aperture 24 formed in plate "for limited angular movement with respect thereto. Substantially rectangular notches 25 having walls 26 providing driving faces are formed in plate I! and are coextensive with those formed in flange 22. The inner ends of side walls 26 of notches 25 formed in plate I! slightly diverge for a purpose that will presently appear.

Disk I1 is resiliently connected to hub 15 for bymeans consisting of leaf spring units or packs each consisting'of a plurality of leaf springs 21 which are disposed rather snugly at one end thereof in recesses 23 formed in flange 22, and at the other end seat rather closely in recesses 25 formed in disk I].

From the structure so far developed it will be seen that should a sudden rotational impulse be I! in clockwise or counter-clockwise l5 will not immediately respond thereto but springs 21' will flex and take a position in surface contact is therefore seen that springs 21 establish a resilierit yielding connection between disk i'i and hub l5, thus avoiding the possibility of transmember to the other. It will moreover be seen that this resilient coupling is double acting for instance, if a vehicle provided with this mechanism, is proceeding down grade with the transmission in high gear and with the clutch disengaged and the operator should suddenly reengage the clutch, hub I5 becomes the driving member, and the sudden rotational impulse transmitted by member l5 to member I1 is absorbed in large part by springs 21. If the resilient connection disclosed were not interposed between hub i5 and disk [1, a severe shock would be transmitted from hub l5 to disk l1 upon reengagement of the clutch with possible damage to the driving mechanism. However, with the present resilient connection incorporated in the mechanism, it is seen, that upon reengagement of the clutch, springs 21 will merely flex in the opposite direction, absorbing any torque impulse that might result in a damag shock to are preferably so designed and tempered to present such a degree of stifl'ness, that during normal torque delivering operations, they will not be flexed to their fullest extent, or come into full contact with the curved faces defining notches 23 and 25, but will only be slightly flexed, accordingly each pulsation of torque delivered by the engine can be absorbed and stored in or cushioned by the springs, resulting in smooth driving torque delivery even at lower speeds when the mechanism is picking the load up.

As shown in the drawings, when leaf springs with walls 23 and 26. It a the mechanism. Springs 21 21 are flexed so as to lie over the full area of the curved faces defining notches 23 and 25, this condition corresponds to any reasonably large 'sudden'impulse transmitting effort from one member to. the other, but in some instances, in order to prevent undue flexing of springs 21 stop means combined with means that securely hold springs 21 in assembled relation with disk l1 and hub |5-are provided.

Disposed on either side of disk l1, and rigidly secured thereto by means of rivets 28 or the like are a pair of plates 29 (Figure 1). Plates 29 are offset at 3| to provide a sliding fit with flange 22 formed on hub I5. Plates 29 are further provided with recesses 32 which are coextensive with recesses 25 formed in-disk |1 inwardly to the periphery of disk l1, where the walls thereof diverge as shown in Figure 4 of the drawings.

The clearance provided between springs 21 and the diverging walls of plate 29 is suflicient to allow normal flexing movement of springs 21 under fairly severe conditions and it will be noted that the outer portions of the walls deflning recesses 32 in plate 29 are flush with the recesses 25 formed in plate l1, and therefore form additional driving faces, and the inner extremities of recesses 32 form stops, so that when springs 21 have been flexed to a predetermined normal extent, the outer springs 21 are in contact with the diverging walls of plate 29, and a positive drive is thereafter established between disk l1 and hub l5. It is to be understood that springs 21 are designed to absorb any reasonably large torque impulse without flexing sufficiently to contact the diverging faces of recesses 32. Thus the limiting walls of recesses 32 are seen to constitute a safety measure to prevent springs 21 from being stressed beyond their elastic limit, which might cause them to take permanent set. A slidable connection is provided between the inner periphery of plate 29 and flange 22 to permit their relative movement during flexing of springs 21, by means of shouldered studs 33 which extend through oversize openings 34 formed in plate 29. Pins 33 are inserted in openings 34, and a plate 35 is disposed on opposite sides thereof and through which the reduced portions of pins 33 extend. After assembly, the ends of pins 33 are then headed over as shown in Figure 1. It will therefore be seen that plates 35 are rigidly connected to each other and permit a lim-' curely hold springs 21 in assembled relation with hub l5 and disk l1.

Each facing l9 and 20 cooperates with a suitable annular plate for effecting a driving connection between driving shaft 5 and driven shaft Plate 4| engaging facing I9 is termed the automatic plate and plate 42 engaging facing 20 is termed the positive plate.

The construction of automatic plate 4| and its actuating mechanism will now be described. Plate 4| is of substantial thickness in order that it may possess a" certain degree of rigidity and thereby prevent distortion or warpage under the temperatures and pressures of operation. .Disposed at preferably 120 intervals around the periphery of plate 4| are key slots 43, each of which cooperates with the curved extremity 44 of driving plate or key member 45 which is secured to the flywheel face by means of bolts 45 or the like. Removably disposed between plates 45 and the face of the flywheel are a plurality of shims 3 41 which may be inserted or removed for the purpose of adjusting plate 45 toward and away from the flywheel face. Shims 41 are slotted so that one or more of them maybe removed or inautomatic plate 4| and their heads are acted.

upon by coiled compression springs 49 seating in apertures 5| formed in the rear face of the flywheel web.

Plate 4| is caused to move away from the flywheel web against the action of springs 49 for slipping drive and clutching purposes by means of acentrifugal mechanism responsive to speed variations of the flywheel. Centrifugal weights, designated generically by 52, are preferably six in number and are disposed between the holdback bolts assemblies on therear face of the flywheel. Each centrifugal weight preferably consists of a lever section 53 which terminates at its outer end in a pair of threaded extremities 54. Fitted over extremities 54 are a pair of weight elements 55 and 56, each of them being cut away to provide a recess 51 at each end thereof to accommodate the adjacent hold-back bolt assembly. Centrifugal weights 55 and 56 are segmental in form and are preferably constructed of sheet metal stampings, held in place on the weight levers 53 by means of nuts 58, threaded on members 54. Lever sections53 are of substantial width and extend through chordal slots 6| formed in the flywheel web between each pair of hold-back bolt assemblies. Lever sections 53 carry at their extremities heads 62, each of which is provided with a flat face 63 that abuts the bottom face of an annular bearing recess or groove 64 which is preferably machined in automatic plate 4|. Heads 62 are also provided with-a reaction face to abut the face of the flywheel web, the edge of which is designed for fulcruming engagement therewith during operation of ferring more particularly to Figure 8 of the drawings, each extremity of knife-edge 65 is seen to engage the outer wall of recess 64, while the inner face of head 62 engages the inner 'wall of recess 64, thereby preventing rotation of heads 52 and keeping them in proper assembled relationship at all times. Apertures 6| are seen to be of ample size for the reception of heads-62,

'uniform distribution of pressure around the entire area of the automatic plate is affected. In connection with this structure it should be particularly noted that no expensive machinery operations are required to provide an accurate seat,

for the centrifugal weights because annular v groove 64 is readily machined in plate 4| in a single inexpensive operation and the weights are held in position in operation by a three point contact.

The mass of weight elements and 58, and the number employed in a particular installation is determined by the consideration of the combined pressure that they must transmit in such installation. In the drive and clutch shown, which is for a Plymouth automobile, six equally spaced weight arrangements are employed.

It will therefore be seen, as the speed of the flywheel increases, each weight assembly 52 will gradually swing outward about the edge as a pivot, in response to centrifugal force. As this occurs, the reaction faces of heads 62 will abut and slide on the flywheel web and the knife edge 65 will engage and pivot upon the flat bottom surface of annular grooves 64 in automatic plate 4I, forcing the plate away from the. web and into clutching engagement with facing l8 of disk II. It will be noted that there is very little sliding engagement of parts in the arrangement disclosed and that the contact at 65 is of a knifeedge pivotal character. The sole sliding movement present is between the flywheel web and the reaction faces ofheads 62. This movement is small and little frictional resistance thereto exists, so that plate 4| is given a smooth and easy movement and clutch grabbing is avoided. The positions taken by the parts under these conditions are shown in Figure 3, wherein both weight elements 55 and 56 are seen to be at rest against the flywheel web.

Positive plate 42 is caused to rotate with flywheel 8 and is permitted to move axially thereof for clutching and declutching purposes by means of pairs of ears or lugs II that are provided on ment of throwout levers 82 will now be described.

positive plate 42 at approximately 120 intervals, and are preferably integral thereto. Lugs II extends outwardly beyond the periphery of plate 42 into saddle members I2 which provide drivin faces I3 that closely abut the opposite sides of each lug assembly, and are adapted to rest in sliding engagement therewith. Saddle members I2 are provided with a clearance space indicated at I4 that is sufficient to accommodate lugs Ii throughout their entire range of movement. The lower ends of saddle members I2 are deflected to lie in a horizontal plane and are apertured and secured to the top face of plate 45 by means of cap screws I5 or the like. Saddle members I2 are preferably formed of sheet metal stampings since their design renders this material entirely suitable for the purpose. It istherefore seen that positive plate 42 is mounted for rotation with flywheel 8 in a very economical manner and is at the same time permitted to move axially thereof throughout a limited range of movement.

Plate 42 is normally urged toward the flywheel web by means of a compression spring II that rests against seats 18 extending inwardly from the inner periphery of plate 42, and associated with each seat I8 is a rib I8 that serves to space the outer convolution of-the springs 11 from the inner wall of plate 42, so that circulation of air can take place therebetween. The otherend of spring 11 seats upon and reacts against a collar 8| that in turn firmly rests against a plurality of throwout levers 8 2. Throwout levers 82 are preferably three in number so that collar 8|, in response to the action spring I1 can rock into a stable position on a three point support and thereby exert an equal pressure upon each lever. The outer end of each throwout lever 82 is disposedbetween each pair of lugs 'II and is journaled therein on a pin 88 passing through aper- .levers. ends of levers 82 are moved towards the flywheel porting member tures in lugs II. In view of the fact that pins 83 abut walls I8 of saddle members I2, no other means than this is required to hold them in assembled position in the mechanism. Provided on opposite faces of levers'82 are curved fulcrum 5 faces 84 and 85 respectively. Fulcrum face 84 cooperates with the outer face of plate 45 when declutching operations are being effected, and fulcrum face 85 cooperates with a hardened steel plug 88 that is frictionally fitted in an aperture 81 formed in the top of saddle member I2.

From the structure so far developed, it will be seen that positive plate 42 is urged toward the flywheel web by direct pressure of spring 11 by virtue of its seat thereon, and isfurther urged towards the flywheel web by an amplified pressure by the other end of spring 11 which seats upon levers 82 and exert an amplified force upon plate 42 due to the force multiplying effect of the It is further seen, that when the inner web, fulcrum faces 84 will contact with the top of plate 45, thus urging pivots 83 away from the flywheel web, and since pivots 83 are journaled in ears II plate 42 is accordingly given a withdrawing movement. Of'oourse at all other times fulcrum faces 85 formed on levers 82 are held in contact with plugs 86 by virtue of the pressure exerted on levers 82 by spring 11, thus urging plate 42 toward the flywheel web.

Formed on the top face of lugs II are apertured ears 88 through which a pin may be inserted to hold throwout levers 82 in assembled position with the rest of the mechanism when assembly and disassembly operations are being carried out. The mechanism for causing declutching move- Cooperation with curved faces 8I formed on the inner extremities of levers 82 is the flat face of ball race 82- which cooperates with anti-fric- 4( tion balls 83 disposed therebetween and a similar ball race 84. Ball races 92 and 84 are held in loosely assembled relation with respect to each other by means of the usual retainer member 85.

Ball race 84 is rigidly mounted upon sleeve 86, 4:

which is slidably mounted upon a hollow sup- 81 which is preferably integral with clutch housing I and is machined and ground so as to be in exact alignment with shaft 5 when the clutch is assembled, and to provide 5 a'close fit with sleeve 88. Supporting sleeve 81 is spaced considerably from driven shaft II and is accordingly independent thereof. Sleeve 86 is provided with bore 88 into which a grease fltting I8l-of well Bore 88 communicates with an axially extending passage I82 formed in sleeve 88 so that lubricant introduced through passage 88 provides lubrication for axial movement of sleeve 86 and also provides lubrication bearing assembly, since passage I82 extends to a passage I82 communicating with the anti-friction bearing.

To prevent rotation thereof, sleeve 88 may be keyed or splined upon support 81, in any suitable a manner but I prefer to provide an apertured lug I88 on sleeve 86 which is slidably associated with a stud I84 threaded into housing I. It will accordlngly be seen that stud I84 prevents rotation of sleeve 88, but at the same time permits free 7 axial sliding movement thereof upon its support 81. Formed on opposite sides of sleeve 88 are lugs I85 which cooperate with throwout fingers I88 (Figures 1 and 6) mounted on throwout shaft M1 in well known manner to produce declutch- 1 known construction is tapped. 5:

for the anti-friction ball 6 is independent of saddle member 12, therefore,

journaled in and extends outwardly of the clutch housing and carries on the end thereof a conventional clutch pedal linkage member (not shown) for imparting rotational movements to shaft I01.

It will be particularly noted that driven shaft H fits loosely into supporting sleeve 91, which is stationarily mounted in the housing, and therefore substantial eccentric or angular misalignment of driving shaft 5 and driven shaft can have no eifect whatever upon the operation of the throwout bearing assembly. Moreover, since there is slight possibility of driving shaft 5 being thrown out of alignment and the bearing face of supports 91 is carefully machined to lie exactly parallel to the driving shaft 5, their permanent alignment is assured and the throwout bearing assembly, providing spring 11 is properly constructed, will cause plate 42 to be disposed parallel to automatic plate 4| at all times regardless of whether the clutch'is engaged or disengaged. Moreover, levers 82 will be held tight at all times regardless of manufacturing inaccuracies or inaccuracies that arise due to wear by the three point engagement of collar 8| with the levers. During clutching and declutching operations the ends of levers 82 will also have a three point support on the face of the throwout bearing assembly, while the throwout bearing is positively maintained in proper alignment by virtue of its stationary guiding ating pressures at all times with a low cost construction.

It should, moreover, 'be noted that due" to the entire absence of an obstructing rim on the flywheel and of the usual cover or any other structure associated with the clutch mechanism that might impede air flow induced by the rotation of the clutch elements, or inhibit free radiation of heat therefrom and also the plane face of the flywheel beyond the driving face thereof, dissipation of heat from the clutch elements by radiation and convection is extremely rapid and there is no tendency to cause overheating and drawing the temperature of springs 21 even under severe conditions of slipping drive, making the incorporation of the torsional dampener thoroughlypractical for the first time in a slipping drive of the general type disclosed. Moreover, as the facplate 45 may be adjusted toward and away from v the flywheel by means of shims 41 interposed therebetween, if it is found at the factory upon assembling the mechanism that positive plate 42 is disposed in non-parallel relation with automatic plate 4|, shims 41 may be inserted or withdrawn from the proper saddle members 12 to bring about parallel relation of the plates. As has been pointed out, plate 45 i.-. held in place on flywheel 8 by means of a single molt 45, which saddle members 12 may be removed from the clutch mechanismwithout in any way disturbing the shims 41 and a proper adjustment will there-.

by be maintained. It is contemplated that" this adjustment be in the nature of an initial factory adjustment for the reason that after the clutch mechanism has been in use, there is no tendency for plate 42 to work itself into non-parallel relation with automatic plate 4| because the wear that does occur on the faces of each lever 82, will occur to an equal extent upon each one of them, since they are acted upon by an equal force, namely one third of the total pressure exerted by spring 11, when the spring is properly designed,

due to the three-point nature of the connection existing between the spring and the levers.

The clutch mechanism disclosed in Figure 1 is shown in what I term the automatic position with the positive plate 42 spaced from the autodesired to effect a driving connection from the engine to the rear wheels, the vehicle may be placed in any gear desired and the latch above referred to operated in order to release the clutch pedal and allow it,to move into its retracted position. This retraction of the clutch pedal allows the throwout bearing assembly to move to the right under the influence of springs Tl, which, acting through levers 82 brings positive plate 42 into clutching engagement with driven member Such operation is desirable or even necessary for severalreasons.

the battery is low, it I is sometimes desirable to connect the driving and driven shafts in positive engagement so that the car can be pushed or coasted in order to turn the engine over, or when stopping on a steep hill, a positive engagement of the clutch in low or in reverse gear will provide an additional emergency brake that cannot be inadvertently released, or if the motor stalls due to lack of fuel or any other cause, the car can be pulled out of any dangerous position by driving the car in low gear with the starting motor.

For instance, in the winter when the motor is cold and During all other normal driving operations,

the positive plate is held in the position shown in Figure 1 by means of the throwout mechanism and latch above referred to.

With the above described clutch mechanism installed in a motor vehicle having a conventional three speed transmission, if it is desired to start the vehicle and the parts are in the position they are shown in Figure 1, and the vehicle is on substantially level ground,'the transmission is placed in high gear and the engine accelerated. As. the engine gains speed, centrifugal weights 52 gradually swing outwardly and cause automatic are heldunder control and do not vibrate or undergo any other desirable movements. Moreover, any possible irregularity of clutch engagement is smoothed out 'so far as torque delivery is concerned by means of the dampener assembly previously described.

As the weights swing further outwardly, a torque of gradually increasing magnitude is transmitted to the rear wheels due to the reaction of spring 11, which is undergoing compression. The vehicle is thus started smoothly and without shock. When the vehicle, and consequently the engine, obtains suflicient speed, the weights will have swung out to their furthermost limit and will rest against the flywheel web and the plates will be in tight engagement with no slippage between them, and an automatic drive is thus established from the driving to the driven shaft. In this connection it should be noted that when the positive plate moves in response to movement of plate 4|, throwout levers 82 will swing out of contact with the face of ball race 92 and therefore no wear of the ball bearing unit will take place under these conditions.

When operating the vehicle in this manner all that is necessary to bring it to a stop is to release the accelerator and apply the brakes. When the vehicle has decelerated to a speed corresponding substantially to engine idling speed through the combined braking action of the engine and the brake mechanism, centrifugal weights 52 will move inwardly to their neutral position and release the clutch and the vehicle may be brought to a complete stop by continued application of the brakes or if traflic conditions permit, the accelerator may be depressed and the engine speed accelerated to cause almost immediate reengagement of the clutch and the vehicle is again picked up in high gear. When operating in high gear or any other gear, and a grade is encountered that requires more torque than the engine can deliver in that particular gear, under the engine speed conditions existing at the time, the engine will naturally decelerate under such excess load, and when sufllciently decelerated, weights 52 will swing inwardly to a slight extent and permit slippage between the clutch plates. Since it is an inherent characteristic of an internal combustion engine to deliver more torque as the speed thereof is increased up to its peak of torque output, the speed of the engine, through the slipping drive conditions existing at this time, will be accelerated sufliciently for it to develop sufiicient torque to carry the vehicle over the grade, thus doing away with the necessity of shifting the transmission into a lower gear so long as the engine can deliver the required torque. As the vehicle gains speed up the grade, or the vehicle again reaches substantially level ground, weight 52 will again swing out and contact with the flywheel web and will thus exert suflicient pressure on automatic plate 4i to again establish a non-slipping drive between the clutch plates and the driven member.

This mode of operation, which permits operation of the usual motor vehicle in high gear for normal starting and operation is made possible by the lubricated character of the facing material that is employed in the present clutch mechanism in combination with eflective ventilating and dust removing capacities of the present clutch structure. It is, therefore, seen that this mechanism constitutes a variable speed drive as well as a clutch mechanism.

When the automatic plate, in response to the centrifugal weights, has moved to engaging position against the action of its hold-back springs and the weights lie in contact with the'flywhe'el web, the positive plate may be backed away from the remaining clutch plates by manual depression of the clutch pedal. There is then no contact between the plates and no driving connection between the driving and driven shaft. In traflic, when it is desired to get the vehicle away quickly and in starting up grades, the clutch pedal may be operated in this manner to disengage the clutch between each gear shifting operation as in a vehicle of the type provided with a conventional manually operable clutch. However, with the present drive and. clutch mechanism, it is contemplated to start the vehicle in high gear under normal operating conditions.

In connection with the device so far developed, it will be seen that a device is produced which provides controlled free-wheeling without the necessity of imposing a free-wheeling unit between the engine and the final drive. As soon as the engine is operating in high gear at any substantial speed, all that it is necessary to do to free wheel, is to release the accelerator and to momentarily depress the clutch pedal from its automatic position into its manually declutched position and shortly thereafter, due tQJ-the engine dropping to idling speed, weights 52 will ,cause separation of the clutch plates. The

clutch pedal is then released and returned to normal automatic position. The vehicle will then coast as there is no torque transmitting connection between the engine and the rear wheels. When it is again desired to drive the vehicle under the power of the engine, the engine is accelerated which will cause the centrifugal mechanism to reengage the clutch plates.

Cooling of the clutch elements and removal of any solid lubricant freed from the clutch facings is eifected by air current induced by the rotation of the clutch elements and drawn into the mechanism through screen 3. The air current is drawn along the cutch axis and thence flows'outwardly on the faces of the clutch plates, a portion of the air streamentering apertures l8 in disk I! and flowing on the other side thereof, and between the automatic plate and the flywheel web.

The continuous outward flow of ,air over both faces of disk i1 effectively cools all of the clutch elements, and at the same time prevents theconduction of heat inwardly to the dampener assembly, thereby avoiding the possibility of drawing or seriously modifying the temper of leaf springs 21 thereof.

The heated dust laden air may be exhausted in any desired manner. In the present instance, however,'I prefer to exhaust the air from the clutch housing through screen 3, one-half of screen 3 functioning as an air inlet and the other half as an outlet for the heated air, an arrangement that has proved to be very satisfactory'in practice.

Referring to Figure 9 of the drawings, the clutch mechanism disclosed in Figure 1 is shown, with a modified spring construction and modified throwout bearing assembly incorporated therein. In view of the fact that many of the parts are of the same construction and have the same functions as those shown in Figure 1 and the entire device functions in the same general manner as that heretofore described, like reference .characters will be given to like parts. In the tween annular members reacting against positive plate 42 and the inner ends of levers 82. Positive plate 42 is provided with an annular seat III against which an annular reacting plate H2 having a flange H3 is adapted to rest. Plate H2 receives the reaction of the springs and transmits it to positive plate 42 and is made of sheet metal in channel form to give the same rigidity. Plate II 2 is provided at suitable intervals around its periphery with depressed portions H4 which are adapted to center and. form a seat for one end of compression springs H5. Preferably, but not necessarily, interposed between springs H5 and plate H2 are heat insulating washers H6, which may consist of any suitable material having the proper heat insulating properties, for preventing the transfer of heat from 'positive plate 42 to springs II5 so that their proper temper may be maintained under severe conditions of abuse of the mechanism.

The other ends of springs H5 cooperate with annular plate III which is provided with annular depressions H8 for centering the springs. Springs H5 seat directly against plate III, which is provided at 120 intervals about its periphery with offset portions to receive throwout levers 82 and plate I I! is reenforced in this region by suitable forming operations. The inner edge of plate in is provided with a tubular portion extending toward the flywheel web and which terminates in an annular flange I2I normal to the clutch axis. Seating on flange -I2I and preferably secured thereto by spot welding or the like is a relatively thick steel ring I22 for a purpose that will become apparent. Ring I22, in response to the action of spring H5, is urged to the right and rests against curved faces I23 formed on throwout levers 82. Throwout levers 82 extend through slots in the flange of plate III for cooperation with ring I22. Curved face 9I formed on throwout levers 82 cooperates with ball race 92 in the manner previously described. In view of the fact that levers 82 are three in number, the action thereof would producelocalized stresses in flange I2I if it contacted them directly, therefore ring I22, being of substantial thickness and rigidity, distributes the reaction pressure of the throw out levers around the entire periphery of flange I2I, which is of relatively light gauge metal, thereby avoiding distortion thereof.

While plate II'I-has been described as having offset portions to allow swinging movements of levers 82, it is to be understood that in some instances, where plate II! is spaced sufficiently from levers 82, plate III may consist of a complete annulus. Moreover, plates H4 and II! have been shown and described as consisting of sheet metal, and although this material is preferred, due to its low cost and workability, it is to be understood that cast material may be employed without departing from the spirit of the present invention. 7

It will be seen, from the structure just described that the spring means here employed operates in substantially the same manner as the single spring 'I'I in the modification of the invention previously described. Flange I2I and ring I22, which correspond to collar. in the previous modification, are free torock and will assume a. stable position in contact with all three throwout levers 82 with a three-point support, so that each lever 82 is held tight at all times and each takes one-third of the total pressure exerted by springs H5. The use of the spring cluster in this form of invention in place of the spring "in the first form described permits more facile and lower cost production due to the lower cost and greater ease of securing uniformity of the smaller springs.

A modified form of throwout mechanism is also disclosed in connection with this embodiment of the invention wherein means are provided for lubricating the pilot bearing for shaft II'. Ball race 94 is rigidly mounted upon a sleeve I25 which is mounted for axial sliding movement upon a support I26, which is supported from the clutch housing in a manner similar to support 81 disclosed in Figure 1 of the drawings. However, in the present instance support I26 is of special configuration, having anannular offset portion I2'l providing an annular chamber I28.

Driven shaft I I is provided with a central bore I28 which extends entirely through reduced portion I2 of shaft II in one direction and at the other communicates with a transverse bore I3I into which is tapped a suitable grease fitting I32 of well known construction. The annular offset portion of support I26 is cut away preferably at the top thereof sufliciently to allow the 'introduction of a greece gunfor cooperation with grease fitting I32 and sleeve I25 is likewise apertured in the upper region thereof.

It will be I seen that rotation of grease fitting I32 with shaft web and which is provided with a suitable grease retaining construction that prevents loss of lubricant to the clutch plates.

Lubrication for the sliding movement of sleeve I25 upon support I26 is provided by a' grease fitting I33 which is tapped into apassage I34 communicating with a lubricant distributing groove I35 located in sleeve I25. Access to this grease fitting is also gained through screen 3.

Formed on opposite sides of sleeve I25 are lugs I36 which cooperate with throwout fingers I31 connected by yoke I38. Rigidly secured to yoke I38 are shafts I 39 and MI which are journaled in the clutch housing in well known manner (not shown). Mounted on the end of shaft ,I4I is the usual clutch pedal linkage (not shown) with which is associated a suitable latch of the character above mentioned for holding the clutch elements in automatic position. Formed on sleeve, 'I25 is an apertured ear or lug member I42 which cooperates with a stud I43 secured in the clutch housing to prevent rotation of sleeve I25 on support I26, and at the same time permit axial sliding movement thereof as explained in connection with the modification of the invention in the figures previously described.

Theoperation of this embodiment of the invention is substantially the same as that previously described, and therefore will not be repeated.

The invention may be embodied in other speciflc forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the" appended claims rather than by the foregoing description, and all changes which come within the United States Letters Patent is:

1. In a drive and clutch mechanism, a drivin member providing a flat reaction wall and having apertures formed therein; a driving clutch plate mounted for rotation with said driving member and for movement axially thereof; centrifugal means for urging said clutch plate away from said driving member. when said driving member reaches a predetermined speed, said centrifugal means comprising a plurality of weight levers extending through said apertures and having heads thereon disposed between said reaction wall and a. fiat surface provided on said driving clutch plate, said heads being of a size to pass easily through said apertures and means associated with said driving plate for retaining said levers in assembled position, and for compelling said heads to rock about definite axes on said fiat surface of said driving clutch plate, comprising an inwardly facing wall provided on said clutch plate and abutting the outer portions of said heads 2. The drive and clutch mechanism set forth in claim 1 wherein said retaining means comprises an annular groove formed in said driving plate and presenting faces against which said heads are adapted to bear to prevent rotational movement thereof.

3. In a drive and clutch mechanism, a driving member; common means mounting an automatic and a positive plate for rotation with said driving member and for movement axially thereof; said means comprising bracket assemblies which are adapted to embrace lug portions provided on one of said plates, said other plate having recesses in which portions of said brackets are adapted to seat; a driven member; frictional means associated with said driven member mounted for movement axially thereof and adapted to be engaged and clamped between said plates and driven thereby; and centrifugallyoperable means associated with said automatic plate for causing the same to engage and drive said frictional means when said driving member reaches a predetermined speed.

4. In a clutch mechanism, a flywheel having a substantially plane face extending to the outer periphery thereof; a driving plate mounted for rotation with said flywheel and having a driving face disposed substantially in the plane of said flywheel face; a second driving member; a driven member disposed, and adapted to be gripped between said driving members, said last-named members being disposed wholly to one side of said flywheel face; means for forcing said drivin members-into engagement with said driven member and for establishing a slipping, power-transmitting drive therebetween when said driving members attain a predetermined speed; means for coupling said driving members to. said flywheel for synchronous rotation therewith, said coupling means being disposed outwardly of the outer periphery of said members and being so designed as to present surfaces having negligible circumferential area, whereby air may flow freely outwardly over said members and rapidly remove heat therefrom during operationof the mechanism, said coupling means also supporting spring reaction means for said second driving member, thereby eliminating the need for a cover member and further increasing the heat dissipating capabilitles of the mechanism.

5. The mechanism described in claim 4 wherein said coupling means comprises keeper members secured to the face of said flywheel.

6. The mechanism described in claim 4, wherein said coupling means comprises apertured keeper members secured to the face of said flywheel and one of said driving members is provided with lugs which extend through said keeper members.

'7. In a clutch mechanism, in sub-combination, a rotatable supporting member; a driving plate having recesses provided in its periphery; a plurality of elements secured in said member and having leg portions disposed in said recesses to 'thereby couple said driving plate and said member; and a second driving plate and a plurality of a centrifugally operable lever element having a fiat elongated configuration, said element being provided at one end thereof with a fulcrum portion extending from side to side of said element and disposed at right angles to its longitudinal axis, said element being provided at its other end with a bearing face disposed substantially at right angles to its longitudinal'axis, and means for securing a centrifugal mass to said element in surface engagement with said bearing face, comprising at least two longitudinally disposed threaded members carried by said lever element and projecting beyond the bearing face thereof and extending through said centrifugal mass, said centrifugal, mass comprising a plurality of metal plates.

9. In a drive and clutch mechanism, adriving member; an automatic plate and a positive plate mounted for rotation with said driving member and for movement axially thereof; a driven member; frictional means associated with said driven member mounted for movement axially thereof and adapted to be engaged and driven by and clamped between said plates; centrifugally operable means associated with said automatic plate for causing the same to engage and drive said frictional means when said driving member reaches a predetermined speed, resilient means associated with said positive plate for opposing the action of said centrifugal means; lever means for withdrawing said positive plate into disengaged position against the action of said resilient means; means fulcruming said lever means on said driving member comprising a plurality of apertured members, having fulcruming faces, secured to said driving member and through which said lever means extends, and means associated with said apertured members permitting adjustment thereof toward and away from said driving member, whereby substantial parallelism of said driving member and said positive plate may be established.

10. In a drive and clutch mechanism, a driving member; an automatic plate and a positive plate mounted for rotation with said driving member and for movement axially thereof; a driven member; frictional means associated with said driven member mounted for movement, axially thereof and adapted to be engaged and driven by and clamped between said plates; centrifugally oper-v able means associated with said automatic plate for causing the same to engage and drive said frictional means when said driving member reaches a predetermined speed, resilient means associated with said positive plate for opposing the action of said centrifugal means; lever means for withdrawing said positive plate into disengaged 1i ward and away from said driving member, whereby substantial parallelism of said driving member and said positive plates may be established, said means comprising a plurality of shims disposed between said apertured members and the face of said driving members; and means whereby said apertured members may be removed from said driving member without disturbing said shims.

11. In a clutch, in sub-combination, a pair of members mounted for rotation and for relative axial movement; means for forcing said members away from each other comprising a plurality of levers having fulcrum portions disposed between said members; and means for holding said levers in assembled relation with said members; comprising an arcuately shaped recess, having inner and outergcylindrical walls, formed in one of said members and in which the fulcrum portions of said levers are chordallydisposed; the fulcrum portions of said levers each contacting the outerwall of said recess at two points and contacting the'inner wall of said recess at one point, for restraining said fulcrum portions against substantial bodily outward and inward movement, respectively, the fulcrum portion of each lever having a relieved portion adjacent the outer cylindrical wall of said recess for permitting said levers to rock outwardly without interference therewith.

12. The device described in claim 11, wherein said fulcrum portions of said levers are adapted to fulcrum in said recess and react against surface portions of said other member.

ROBERT P. LEWIS. 2o 

